1. Field of Invention
This invention relates generally to the field of sporting goods and equipment, and more particularly, to portable means for supporting a net required for sports such as tennis, badminton and volleyball.
2. Prior Art
During the past decade, interest and participation in the sport of tennis has increased to an all-time high in the United States and in many countries of the world. In the United States alone, it is estimated that over 20 million people play tennis.
All over the country, new tennis clubs are being constructed and private and municipal tennis courts are being put in at an unprecedented rate. Yet, the public's demand and need for tennis courts remains unsatisfied. For many tennis players the choice is often between long waits at municipal courts or the expense of membership in a private club or tennis court rental fees. For young children and teenagers interested in tennis, there is typically no choice. They must wait for a public tennis court for periods of time which are often far greater than their actual playing time, thereby wasting time which could otherwise be used for exercise or study.
There are many available areas having flat, hard (paved or concrete) surfaces, such as school yards and outdoor parking lots which, when not being used for their primary purpose, are suitable for the playing of tennis (or other net sports). Yet, while the public's need for tennis courts is generally unsatisfied, many such available areas, having surfaces suitable for tennis, remain empty and unused, particularly on weekends when the demand for tennis courts is at its peak. What has been required, but heretofore not available, is a knock-down, portable means for erecting a tennis (or other) court on such surface without drilling into or otherwise altering the surface. The present invention discloses such means, thereby satisfying the long-felt need to utilize areas such as school yards and parking lots for tennis and other net sports when these areas are not being put to their primary uses.
The prior art teaches means for supporting net poles in the upright position which utilize ground anchor means such as augers or helically shaped anchors for securing the posts. U.S. Pat. No. 3,076,532, issued to N. V. Frye, discloses ground anchors which are embedded in the ground surface in order to provide support. Such support means are unsatisfactory for portable tennis court use on parking lots and school yards because they cause permanent holes in the surface. Moreover, the ground anchors disclosed in the Frye patent are adapted for use on a ground surface which is comparatively soft and yielding, such as sod, gravel and the like. This is a significant limitation if such anchors are to be used in the type of ground surface particularly suited for tennis, such as asphalt or concrete.
U.S. Pat. No. 3,216,681, issued to P. Tagliavia discloses a base, typically weighted with sand or other dense materials, for supporting large sunshades of the beach-umbrella type. The base consists of a pair of hollow pan-shaped members which receive the shaft of the umbrella and which are filled with stones, sand bags or the like. The pan-shaped members have a circular cross-section, so the ballast material is evenly distributed around the shaft. While such a base support may be suitable for supporting sunshades vertically, it would not be suitable for supporting poles attached to nets which require a substantial degree of tension. This is because the force of a net under tension (acting in a direction perpendicular to the pole) would tend to cause the base support, and the poles supported thereon, to lean inward toward the center of the court, thereby reducing the tension in the net. In addition to the required tension of the net, the weight of the net and the impact forces of the ball, particularly a volleyball, would further cause the base supports and poles to lean inward, even to a point beyond their centers of gravity which could cause them to topple over. To utilize the structure disclosed by Tagliavia for supporting a tennis or volleyball net would require very great ballast weight to mitigate the undesirable tendency of the poles to lean inward. Use of such additional ballast weight would decrease the portability of the device.
In U.S. Pat. No. 582,973, issued to J. W. Beaman, a tripod-like pole support stand is disclosed. This structure does not include a weighted base, and therefore, is even less suitable for use in supporting the poles of a tennis or volleyball court than that disclosed in U.S. Pat. No. 3,216,681 (Tagliavia).
The present invention overcomes the foregoing limitations and shortcomings of the prior art by disclosing a structure which can be used on hard surfaces without drilling holes therein and which can stably support a net having the required tension.